1. Field of the Invention
The present invention relates to mechanism for sorting fish, particularly for sorting fish according to sex.
2. Prior Art
It is known that the sex of a fish of certain species can be detected without slicing open the fish by beaming radiant energy onto the fish belly and guaging the intensity of such energy transmitted through or reflected by the fish belly. For example, the belly of a roe-carrying herring is much more transparent than the belly of a herring not carrying roe. Consequently, by beaming radiant energy onto one side of the belly of a herring and by measuring the intensity of the radiant energy at the opposite side of the herring belly, it can be determined whether the herring is male or female.
Cuthbert U.S. Pat. No. 3,859,522 discloses a fish sorter using a radiant energy source and energy-responsive sensors for detecting the sex of a fish. However, this patent does not disclose any specific mechanism for actually sorting the fish in accordance with the energy intensity measured by the sensor.
Norwegian Pat. No. 90,487 discloses another fish sorter having a sex detector including a radiant energy source and an energy-responsive sensor. In accordance with this patent, fish are transported past the detector by a conveyor, and the detector signals a gate or gates for diverting the fish according to sex as they drop from the discharge end of the conveyor. If the conveyor of this patent were run at high speed, fish or different weights would be thrown to different locations and the fish sorter would not sort fish effectively. In addition, since there is a time delay from the time of sex detection and the time of fish discharge from the conveyor, the control mechanism for the diverting gates is complicated.
Hauptmann U.S. et al Pat. No. 4,051,952 discloses yet another fish sorter using a radiant energy source and energy-responsive sensors. However, the apparatus of this patent utilizes a different type of sorting mechanism than the sorter of the present invention.